KR20010071329A - Compounds made of polyamide and perfluoroalkyl substance(s) and mixtures of these compounds with additional polymer substances, a method for the production thereof, and their use - Google Patents

Abstract

The present invention relates to compounds which consist of polyamide- and perfluoroalkyl material (s) and can be used, for example, as compact materials and mixtures of these compounds with further polymeric material (s). The invention also relates to aliphatic and / or partially aromatic homo- and / or copolyamides and / or polyester amides and / or polyether amides and / or polyesterether amides and / or polyidamides and / or polyamideamines and And / or mixtures of these polyamide compounds with additional polymers and also methods for preparing said compounds in which the modified perfluoroalkyl material (s) are mixed in one or multiple stages and then or reactively converted thereafter. . It is an object of the present invention to improve the homogeneous miscibility of perfluoroalkyl materials in polyamide melts.

Description

Compounds of polyamide- and perfluoroalkyl materials and mixtures of these compounds with additional polymeric materials, methods for their preparation and use thereof. A METHOD FOR THE PRODUCTION THEREOF, AND THEIR USE}

In the search for suitable polymer materials for core reactors (nuclear reactors), PTFE has been found to be exceptionally radiation sensitive, as opposed to its high chemical and thermal stability. It is already decomposed at low energy doses, not only under inert conditions but also in the presence of oxygen, already brittle at 0.2 to 0.3 kGy and brittle at less than 100 kGy.

From about 360 ° C., thermal degradation is significantly overlapped with pure radiochemical decomposition.

The statistical course of radiochemical decomposition results in reaction products with a wide chain length distribution.

Irradiation of PTFE in the presence of oxygen forms peroxy- and alkoxy radicals from the perfluoroalkyl radicals that occur first. Through the intermediate stages of alkoxy radical formation, the final perfluoroalkyl radicals decompose stepwise while forming chain shortening and carbonyl dichloride.

By comparison, by-product alkoxy radicals result in fluorinated perfluoroalkanoic acids and the final perfluoroalkyl radicals:

Superfluorinated dibasic acids are also produced in very small amounts, since two lateral radical centers can also occur in the perfluorocarbon chain. The emulsion and suspension polymers of unsintered and non-compressed PTFE are of fiber-felt nature. For example, the anti-adhesive and slide (slip) properties of PTFE cannot be transferred to other media by treating with aqueous or organic dispersants, polymers, pigments, lacquers, resins, or lubricating materials, because the PTFE This is because it cannot be homogenized and tends to form agglomerates and aggregates, floats or precipitates.

By the action of high energy radiation (beam) with an energy dosage of about 100 kGy, a partial powder of the polymer chain is obtained due to the partial decomposition of the polymer chains. This powder still contains loose agglomerates, which can be easily divided into main particles having a particle diameter of <5 μm. When irradiated in the presence of the reactants, functional groups are formed in the polymer. When irradiated in air, a carboxy group is obtained according to GI. (9.22) (and subsequently by hydrolysis of the -COF- group by moisture in the air). If (NH ₄ ) ₂ SO ₃ is added before irradiation, an S-containing group can be obtained. Because these functional groups greatly reduce the hydrophobicity and organic exclusion of PTFE, the resulting fine powder can be well homogenized by other media. The positive properties and high chemical and thermal stability of PTFE, such as excellent slip, separability and dry lubricity, remain the same. The carboxy- and sulfone airways to which the and fluorinated chains are bound also have high chemical inertness.

Due to the insolubility of PTFE and its degradation products (except for materials with very low molecular weight), ordinary molecular weight determination methods cannot be used. So molecular weight measurement should be done by indirect method. [A.Heger et al., "Radiochemical Technology for Polymers", Berlin Academy Publishing 1990].

Incompatibility with other materials is disadvantageous in many respects. However, it can be modified by chemically activating PTFE through a known method with (1) sodium amide in liquid ammonia and (2) alkalialkyl- and alkali-aromate-compounds in aprotic inert solvents. . Such denaturation may result in improved interfacial exchange action through reactive or merely adsorptive forces.

PTFE decomposition products are used in a wide variety of applications and may therefore be used as additives to synthetic resins for the purpose of achieving slipperiness or detachability. Fine powder material is present as a filling component, somewhat finely dispersed in the matrix [Ferse et al., Plastics and Rubber, 29 (1982), 458; Ferse et al., DD-PS 146 716 (1979)]. When the matrix component is dissolved, the PTFE fine powder can be removed or recovered.

In the field of use of PTFE fine powders, physical property improvements can be achieved compared to fluorocarbon commercial additives but are disadvantageous for applications with high incompatibility, insolubility, loose bonding and heterogeneous distribution.

FIELD OF THE INVENTION The present invention relates to the chemical, mechanical and material industries, for example slide bearing materials, slide films, slide foils, slide lacquers, partial or compact materials with oleophobic and / or hydrophobic or such properties, molded parts, fibers For yarn, fleece and / or other fabric surface formations, membrane materials, as compact materials, as surface modification components, as blending components, as additional materials or as additives, as lacquer additives, or as lacquer materials Compounds of polyamide- and perfluoroalkyl materials which can be used, and mixtures of these compounds with further polymeric materials, and methods for their preparation and their use.

It is an object of the present invention to improve the homogeneity of perfluoroalkyl materials in polyamide melts (melts).

This object is achieved by the invention indicated in the claims. Further specific embodiments are the subject of the dependent claims.

According to the present invention, polyamide- and perfluoroalkyl materials and their compounds and additional polymers, in which the perfluoroalkyl components are not only homogeneously distributed as fillers, but in most cases are also present in chemical combination with the polyamide components. Mixtures with materials can be obtained by reactive melt modification reactions. Through dissolution of the polyamide matrix components, the perfluoroalkyl component can no longer or no longer be fully recovered as a fine powder.

By using / treating the perfluoroalkyl material modified by the polyamide compound in this melt modification reaction, homogeneous compounds are not directly contained as known, in which the perfluoroalkyl component is not included as an insoluble and incompatible bicomponent. Can be prepared. Perfluoroalkyl components are present in a homogeneous distribution, mostly chemically bonded to polyamide via bonds (bonds) and this is an important advantage for the fields of use. Thus, the perfluoroalkyl component no longer wears off or falls off from the matrix (based) material, as is the separation in the conventional slide bearings as particles through mechanical forces such as friction.

To prepare such homogeneous compounds, modified perfluoroalkyl materials with carboxylic acid groups and / or halogenated carboxylic acid and / or olefin groups are used as functional groups. Radiochemically decomposed and modified perfluoroalkyl materials are used, such as PTFE-fine powders, preferably produced with a beam dosage of at least 50 kGy, preferably with a beam dosage of at least 100 kGy. Modified perfluoroalkyl materials are obtained in the radiochemical decomposition, preferably by the presence of the reactants under oxygen inlet, preferably modified by perfluoroalkylcarboxylic acid and fluorinated perfluorocarboxylic acid groups. .

In the process for producing such compounds, commercial melt mixers (single and double helix extruders, planetary rolling extruders, kneaders, plasticizers for injection molding machines, etc.) are used. PTFE fine powder is either melted with the polyamide mixture or added directly into the melt. 0.01 to 90% by weight of the radially modified perfluoroalkyl material (relative to the polyamide component) is preferably added as PTFE fine powder. As a preferred mass fraction, 1 to 70% by weight of PTFE fine powder is introduced into the polyamide component. In the prior art, the groups connected to the perfluorinated chains had a high inertness, but the product according to the invention surprisingly occurs in the direct melt deformation reaction. Reactive conversion in the melt is carried out at least above the melting point of the polyamide compound (s), preferably above 200 ° C.

In order to prepare such inventive compounds, aliphatic and / or partially aromatic homo- and / or copolyamides and / or polyester amides and / or polyether amides and / or polyesterether amides and / or poly Diamides and / or polyamideamines and / or mixtures of these polyamide compounds with further polymers and modified perfluoroalkyl materials are used.

As the polyamide compound, polyamide 6 and / or polyamide 6,6 and / or polyamide 12 are preferably used in pure form or as filler and / or reinforcement.

In mixtures, polyamide compounds can be used with additional polymers such as polyolefin and / or polyvinyl compounds and / or multiple condensates such as polyesters and polycarbonates and / or multiple addition compounds such as polyurethanes. And such mixtures may be used as starting materials or may be added during blending or may be added to the melt after blending or to be reacted in subsequent steps.

Such subsequent steps include, for example, mixing the resulting compound of a polyamide compound with a perfluoroalkyl material, with additional polymers of polyolefin type and / or vinyl type and / or with multiple condensates and / or with multiple addition compounds and And / or reactive materials may be added and mixed in the next treatment step.

The preparation of the compound and subsequent product is then carried out in a one-step or multi-step process, wherein the compound or its subsequent product can be reactively converted during or following the process.

Additive mixing to the reactant material which does not adversely affect the formation of the compound before and / or during and / or after the reactive conversion of the polyamide compound with the perfluoroalkyl material can be done. The product of this conversion reaction can be further processed to the final product during or after compounding, for example by further reactive conversion by treatment with a high energy beam.

The compounds so prepared can be used as compact materials and / or as surface modification components and / or as compounding materials and / or as binding materials and / or as additives.

Use is in slide bearings and / or in slide films and / or in slide foils and / or in slide lacquers and / or in partial or compact materials with oleophobic and / or hydrophobic or such properties and / or molded parts And / or to fiber yarn- and / or fleece- and / or other fabric surface formations and / or to multilayer (foil) materials and / or to membranes, as pure materials or as additional / component materials and / or lacquer additives And / or lacquer material.

The materials according to the invention can be further treated as a thermoplastic melt and / or as a reactive material or as a solution or from a solution due to their physical properties.

As the process synthesis apparatus, suitable are plasticizers for kneaders, single or double spiral extruders and injection molding machines, i.e. all commercial mixing systems used for plastics processing / blending.

The results are surprising to the expert and above the level of satisfaction. This melt deformation reaction can result in a polymer product which is not yet fully known. Such melt deformation reactions with perfluorinated materials have not yet been described in the art.

Further, the present invention is explained in more detail by various examples.

Example 1

In a laboratory kneader (Brabender), 40 g of PA 6 was calcined at 250 ° C. and 15 g of PTFE fine powder transformed into a 1000 kGy beam was added to the melt. After 5 minutes the compound was removed and the compound was dissolved in formic acid and sprayed onto the polyamide-6-surface. This surface modification resulted in a hydrophobic and oleophobic thin film in which the sliding friction coefficient was significantly lowered (sliding friction coefficient drop rate 40%). The rise from the interface angle (pure PA-6) of 65 degrees to 95 degrees (this compound) was obtained by the measurement of the interface angle (boundary angle) by the water droplet provided.

Example 2

In a laboratory kneader (Brabender), simultaneously plasticization of 15 g of PTFE micropowder transformed with 40 g of PA 6 and 500 kGy beam at 250 ° C. After 5 minutes the compound was removed and the compound was injection molded into a test object for sliding friction testing in a small injection molding process. A 35% drop was observed in the test of the sliding friction coefficient. As a result of measuring the interfacial angle with the water droplets provided, an increase from the interfacial angle of 68 ° (pure PA-6) to 90 ° (this compound) was obtained.

Example 3

In a double helix extruder (ZSK 30, Werner & Pfleiderer), 1 kg / h of PTFE fine powder denatured with a beam of 5 kg / h PA-66 and 4000 kGy was extruded at 280 ° C. The product was assembled and dried.

Compounds were injection molded into test objects for sliding friction testing in a small amount injection molding process. A 45% drop was observed in the test of the sliding friction coefficient.

Example 4

5 kg / h of PTFE fine powder denatured with 5 kg / h of PA-6 and 2000 kGy beam in a double helix extruder (ZSK 30, Werner & Pfleiderer) was extruded at 265 ° C. The product was assembled and dried.

The compound was injection molded into a test object for the sliding friction test by the injection molding process. A 65% drop was observed in the test of the sliding friction coefficient.

The interfacial angle measurement by the water droplets which settled obtained the rise to 105 degrees (this compound) from the boundary angle of 65 degrees (pure PA-6).

Example 5

In a kneader (BUSS AG), 7 kg / h of PTFE fine powder denatured with 5 kg / h of PA-6 and a 2000 kGy beam was melt mixed at 250 ° C. The product was assembled and dried.

The obtained batch is reactively blended in a ratio of polyethylene with dropwise maleic anhydride added in the second step, 10 wt% batch (compound) and 90 wt% polyethylene. It was injection molded into a slide bearing and crosslinked radiochemically to obtain a high temperature form stable slide bearing having a sliding friction coefficient of 40%.

Example 6

In an injection molding machine (Engel), 1 kg / h of PTFE fine powder denatured with a beam of 5 kg / h PA-6 and 4000 kGy was plasticized at 260 ° C. and injection molded into a slide bearing. The slide bearing had a sliding friction coefficient lowered by 45%.

Example 7

5 kg / h of 0.5 kg / h of PA-6 and PTFE fine powder were extruded at 260 ° C. in a double screw extruder (ZSK 30, Werner & Pfleiderer). The melt was extruded as is (on a line) into plate and slip foils.

A 45% drop was observed in the test of the sliding friction coefficient. The interfacial angle measurement by the settled water droplets obtained the rise from the boundary angle of 68 degrees (pure PA-6) to 95 degrees (plate-shaped foil from a compound).

Example 8

In a laboratory kneader (Brabender), 30 g of PA-6 was calcined at 250 ° C. and 30 g of PTFE fine powder modified with a 1000 kGy beam was added to the melt. The compound was removed after 5 minutes and it was dissolved in formic acid in a ratio of PA 6 and 1: 1 and adjusted to a concentration of 15% by weight of polymer. The solution was treated to a pervaporation membrane through a phase inversion method. Measurement of the boundary angle with a straight drop of water resulted in a rise from the boundary angle of 68 ° (pure PA-6) to 90 ° (membrane from compound, thick separation layer), which means strong hydrophobicity. In the case of separation with alcohol-water-mixing, a separation coefficient rise of 120 was achieved at 30 ° C. compared to pure PA-6- and evaporation membranes.

Claims (20)

A compound of polyamide- and perfluoroalkyl material (s) characterized in that the perfluoroalkyl material (s) modified by the polyamide compound (s) are homogenized via a reactive conversion in the melt and Mixtures of these compounds with additional polymeric material (s). 2. Compounds according to claim 1, characterized in that the modified perfluoroalkyl material (s) have a functional group. 3. The modified perfluoroalkyl material (s) of claim 2, wherein the modified perfluoroalkyl material (s) comprises one or more carboxylic acid groups and / or one or more halogenated carboxylic acid groups and / or one or two or more perfluoroalkylene groups as functional groups. Compound to have. A compound according to claim 1, wherein the modified perfluoroalkyl material (s) is contained in the compound in an amount of 0.01 to 90% by weight. A compound according to claim 4 wherein the modified perfluoroalkyl material (s) is contained in the compound in an amount of 1 to 70% by weight. Aliphatic and / or partially aromatic homo- and / or copolyamides and / or polyester amides and / or polyether amides and / or polyesterether amides and / or polyidamides and / or polyamideamines and / or these poly Of the compound according to claim 1, characterized in that the mixture of the amide compound with the further polymer and the modified perfluoroalkyl material (s) are mixed in one or multiple stages and then reactively converted thereafter. Manufacturing method. The polyamide compound (s) of claim 6, wherein the polyamide compound (s) is polyolefin (s) and / or polyvinyl compound (s) and / or multiple condensate (s) such as polyesters and polycarbonates and / or polyurethanes. A mixture with multiple addition compound (s), used as starting material, added during mixing, or added after mixing of the melt, or reacted with the compound in a subsequent step. 7. The polyamide compound (s) according to claim 6, characterized in that polyamide 6 and / or polyamide 6,6 and / or polyamide 12 are used in pure form or in filled and / or reinforced materials. How to. 7. A method according to claim 6, wherein the mixing (mixing) is carried out in a plasticizer of a single- and / or double spiral extruder and / or a kneader and / or an injection molding machine. 7. Process according to claim 6, wherein the reaction conversion is carried out in the melt, wherein the conversion is carried out at a temperature of at least the melting point of the polyamide compound (s), preferably at least 200 ° C. 7. The process according to claim 6, wherein addition mixing to the reactants is effected before and / or during and / or after the reductive conversion. 7. The process of claim 6, wherein further reaction conversion is carried out during or after mixing. 7. Process according to claim 6, characterized in that perfluoroalkyl material (s) is used for chemically decomposed and modified perfluorocarbons (carbon perfluoro). 14. Process according to claim 13, characterized in that perfluoroalkyl material (s) is used as the chemically decomposed and modified perfluoro PTFE, preferably as fine powder. Process according to claim 13, characterized in that as PTFE, PTFE is used that is decomposed and deformed at a beam dosage of at least 50 kGy, preferably at a beam dosage of at least 100 kGy. 14. A process according to claim 13, wherein the PTFE is radiochemically decomposed and deformed in the presence of the reactants, preferably under oxygen inlet. The compound according to claim 6, wherein the compound of polyamide compound (s) and perfluoroalkyl material (s) is further polymerized with polyolefin type and / or vinyl type and / or with multiple condensate (s). Reaction with forming and / or mixing with the reactant material during compounding with multiple addition compound (s) or in subsequent processing steps. Use of the compound according to claim 1, prepared according to claim 6, used as a compact material and / or as a surface modification component and / or as a compounding component and / or as a binding material and / or as an additive. 19. A partial or compact material according to claim 18, as a pure material or as an additional / component material, in a slide bearing or in a slide film or in a slide foil or in a slide lacquer or in a partial or compact material with oleophobic and / or hydrophobic or such properties; Use in forming parts or in fiber yarn- and / or fleece- or other fabric surface formations or in multilayer (foil) materials or in films, or as lacquer additives or lacquer materials. 19. The use according to claim 18, which is further finished as a thermoplastic melt and / or as a reactive material and / or as a solution and / or from a solution.